This is an archived problem from a previous year. Submissions are closed, but you can view the problem and its solution.
As you finish the selfmate puzzle, the church bells suddenly start ringing, echoing loudly in the otherwise empty church. You head up the long staircase to the bell tower, wondering if anyone had been watching you solve the puzzle, ringing the bell just as you completed it.
Reaching the top, you find a smell of bell lingering in the air, almost as if someone had just been there. You then realize that there's a huge bell swinging in front of you, which perfectly explains the smell. Still, the thought that someone might have been observing you leaves you uneasy. Could this be connected to Grinchuk?
Next to the bell, you spot a chessboard with pieces set in what seems to be a chess opening gone wrong after the third move. However, alongside the board, a small note catches your eye. It simply states, "This position was reached after four moves." This detail takes you by surprise, as you could have sworn that only three moves had been played! You sit down, looking over yet another chessboard, wondering how it might connect to the mysterious happenings.
Starting from the initial position, give a sequence of moves that reaches this position in exactly 4 moves (4 moves for White and 4 moves for Black, alternating). Here's an analysis board you can play around on. And here's Offerspill's Discord server, in case you need help understanding the problem. Also join our open Lichess team, where we will organize some tournaments this advent!